Patent Grant
10221509
The present invention concerns improvements to methods for producing articles or garments comprising two leg pieces and one body, for instance pantyhose, tights or the like. Especially, the present invention relates to methods for producing seamless garments of the above mentioned type using a single knitting process onto a circular knitting machine provided with single or double needle bed.
In the field of production of tights, pantyhose and similar knitted articles, there is a continuous search for new methods and systems for automating the knitting process, to obtain a seamless continuous article or garment, knitted on a circular machine in a single production process.
Some searches are based on a process developed in the '60s, which provides for a tubular article to be knitted during a single process onto a circular knitting machine starting from an end of a first leg piece up to an end of a second leg piece, knitting three subsequent tubular portions or sections to form, in addition to the two leg pieces, the body of the article. The tubular article unloaded form the circular knitting machine is then cut in the central area to form an opening around which an elastic edge is sewn to form the body waist. This known process is detailed in the GB-1235361. To increase its fit, the body is knitted with wider stitches, so that the central portion of the tubular article or garment has a slightly greater section than the section of the leg pieces.
The method described in GB-1235361 is very fast as it can be performed on a circular knitting machine with continuous motion. However, the article produced by means of this method had low success as the body, being formed with a tubular fabric with the same number of stitches per raw as the tubular legs, did not fit sufficiently closely. More in particular, the body height was too limited and the elastic edge was too close to the crotch line.
Many improvements to this method have been studied, trying to overcome the limits and drawbacks thereof.
U.S. Pat. No. 2,962,884 discloses a method wherein, after having knitted the first leg piece and before knitting the second leg piece, two pockets of fabric are produced on the circular knitting machine by knitting with reciprocating motion rows of gradually decreasing and then increasingly length. The two pockets knitted with reciprocating motion form the body of the garment, which thus fits more than the body produced with the method originally described in GB-1235361.
However, the method disclosed in U.S. Pat. No. 2,962,884 is particularly slow as most of the garment, and especially the whole body, is knitted by means of reciprocating motion with only one feed, i.e. feeding only one yarn to the needle cylinder and therefore forming only one row of stitches at every rotation of the needle cylinder. Regardless of this inconvenience, at the present time seamless tights are produced using this method. Especially, the seamless tights of the Austrian company Wolford are produced with this method, combining continuous motion for knitting the leg pieces and reciprocating motion for knitting the body.
U.S. Pat. No. 4,022,035 describes a method for producing tights in a single process on a circular knitting machine with a technique similar to that of U.S. Pat. No. 2,962,884. In this further embodiment, while knitting the body central portion with reciprocating motion the needles are precisely selected so as to form the opening of the garment directly onto the circular machine. Also this process is particularly slow, as it is mostly made with reciprocating motion of the needle cylinder.
There is therefore a need to further improve the methods for knitting pantyhose, tights and similar articles or garments having a body and two leg pieces, using a single process onto a circular knitting machine, which overcome or reduce the drawbacks of the known methods that are still used.
To produce an article or garment with one body and two leg pieces by means of a more efficient and faster process, a method comprising the following steps is provided:
Knitting the whole body with a plurality of feeds allows achieving a high production speed. Forming the two side pockets of fabric improves the garment snug-fit. Using the reciprocating motion only for forming the side pockets allows having a particularly regular fabric that is comfortable to be worn, while using the continuous motion for knitting a central or intermediate portion of the body allows decreasing the time necessary to produce the garment.
In some embodiments, the method further comprises the steps of:
In advantageous embodiments, the number of feeds used for knitting the different parts of the garment is always the same. Preferably, above all if Z-yarns and S-yarns are used for forming the various rows of stitches, there is an advantage in using an even number of feeds.
In some embodiments two feeds are used. However, the number of feeds will be preferably greater, for instance four or six feeds, as long as the diameter dimension of the needle cylinder allows it. Generally speaking, the greater the number of feeds, the higher the production speed.
In some embodiments the step of knitting the first pocket of fabric with reciprocating motion comprises the steps of:
Each time the circular needle bed rotates in one direction and each time the circular needle bed rotates in the opposite direction a plurality of rows is formed in a number corresponding to the number of feeds. In some embodiments, the groups of rows formed at every angular stroke of the needle cylinder in one direction and in the opposite direction can have the same length, even if this is not strictly necessary.
In the present description and the attached claims, length of a row of stitches generally means the length represented as the number of stitches. Two rows of equal length are therefore formed by the same number of stitches.
In a mirror-like way, the step of knitting the second pocket of fabric with reciprocating motion comprises the steps of:
Every time the circular needle bed rotates in one direction and every time the circular needle bed rotates in the opposite direction a plurality of rows is formed in a number corresponding to the number of feeds. In this case again, the rows formed at every rotation or angular stroke of the needle cylinder may be of equal or different length.
To achieve better aesthetic appearance and higher tensile strength of the fabric, the plurality of partial rows formed through rotation of the needle bed in one direction or in the opposite direction (i.e. at every angular stroke of the needle cylinder) while knitting the first and the second pocket of fabric with reciprocating motion are shifted one with respect to the other by a suitable number of stitches. This allows a better distribution of stresses in the knitted fabric structure when the garment is worn, thus reducing the risk of breakage, with respect to what occurs if all rows formed at every reciprocating movement of the needle cylinder end at the same point, i.e. at the same column of stitches. Practically, shifting the ends of the consecutive partial rows knitted with reciprocating motion results in these ends being arranged along a band of fabric comprising a plurality of columns of stitches, instead of being concentrated on two columns of stitches.
In some embodiments, the partial rows are shifted with respect to one another by a number of stitches comprised between 2 and 15, preferably between 3 and 10 and more preferably between 3 and 7. In some embodiments, the shifting of the ends of consecutive partial rows is fixed both while forming decreased rows (i.e. rows of decreasing length) and increased rows (i.e. of increasing length). However, this is not strictly necessary. According to some embodiments, while forming the pocket of fabric the number of stitches by which consecutive rows are shifted may be different for consecutive rows and may even change along the extension of the pocket of fabric. For instance, there could be a shifting by N stitches while knitting the first decreasing rows, and then by M stitches, where M is different than N.
According to a further aspect, the invention provides a knitted article or garment comprising a body and two tubular leg pieces, wherein the body comprises two side pockets of knitted fabric, each pocket being formed by a first series of partial rows, constituting the extension of a knitted fabric forming the two tubular leg pieces, the rows of said first series of partial rows having decreasing length starting from the respective leg piece up to a group of partial rows of minimal length of the respective pocket, and by a second series of partial rows, having increasing length starting from the respective group of partial rows of minimal length up to a respective complete row; and wherein said pockets of fabric are formed with a plurality of feeds with reciprocating motion.
The (reciprocating or continuous) motion of the needle cylinder results in a given arrangement of the rows of stitches in the finished garment, corresponding to the trajectory according to which the stitches are formed. In the portions of fabric knitted with continuous motion, the rows are arranged according to a continuous helical line, whilst in the areas of fabric knitted with reciprocating motion the rows are arranged according to a zigzag pattern. Therefore, defining the structure of the various areas of fabric of the garment by indicating the type of motion used for knitting it corresponds to defining an arrangement of the rows of stitches forming the fabric.
Advantageously, the body further comprises a central portion arranged between the two pockets of fabric and formed with continuous motion with a plurality of feeds.
The partial rows formed with the plurality of feeds and corresponding to each reciprocating knitting movement are advantageously shifted with respect to one another, so that the ends of the partial rows are spaced from one another by a number of stitches equal to or greater than 1, and preferably equal to or greater than 2 and more preferably equal to or greater than 3.
According to a further aspect, the invention relates to a knitting machine comprising a needle cylinder with a circular needle bed, a cam mantle and selectors, a plurality of feeds for yarns, and a control unit, wherein said control unit executes a program implementing a knitting method as described above.
Characteristics and embodiments are described hereunder and further defined in the attached claims, which form an integral part of the present description. The above brief description identifies characteristics of the various embodiments of the present invention, so that the detailed description below may be better understood and in order that the contributions to the art may be better appreciated. There are obviously other characteristics of the invention which will be described further on and which will be indicated in the attached claims. With reference to this, before illustrating different embodiments of the invention in detail, it must be understood that the various embodiments of the invention are not limited in their application to the construction details and to the arrangements of components described in the following description or illustrated in the drawings. The invention may be implemented in other embodiments and implemented and placed in use in various ways. Also, it is necessary to understand that the phraseology and terminology used here are only for descriptive purposes and must not be considered as limiting.
Persons skilled in the art will therefore understand that the concept on which the invention is based may be promptly used as a base for designing other structures, other methods and/or other systems to implement the various objects of the present invention. It is therefore important that the claims be considered as comprising those equivalent constructions which do not deviate from the spirit and scope of the present invention.
The invention will be better understood by following the description and accompanying drawing, which shows non-limiting practical embodiments of the invention. More particularly, in the drawing:
The detailed description below of example embodiments is made with reference to the attached drawings. The same reference numbers in different drawings identify the equal or similar elements. Furthermore, the drawings are not necessarily to scale. The detailed description below does not limit the invention. The protective scope of the present invention is defined by the attached claims.
In the description, the reference to “an embodiment” or “the embodiment” or “some embodiments” means that a particular feature, structure or element described with reference to an embodiment is comprised in at least one embodiment of the described object. The sentences “in an embodiment” or “in the embodiment” or “in some embodiments” in the description do not therefore necessarily refer to the same embodiment or embodiments. The particular features, structures or elements can be furthermore combined in any adequate way in one or more embodiments.
In some embodiments the garment or article, indicated as a whole with reference number 1, comprises a first tubular leg piece 3 and a second tubular leg piece 5. Each of the two tubular leg pieces 3 and 5 extends from a respective toe or end (not shown), that can be open ore closed, up to a body 7. The tubular leg pieces may extend up to ends forming respective feet of the article, for instance in the case of tights or pantyhose. In other embodiments the tubular leg pieces 3 and 5 may be shorter and can comprise even few rows of stitches so as to form, together with the body 7, a sort of knickers.
The body 7 has an opening 9 surrounded by a finishing edge indicated with 11, preferably an elastic edge. The elastic edge 11 is shown in
In advantageous embodiments the body 7 comprises three portions: a central portion 15 and two side portions 17 and 19. As it will be better detailed below, each of the side portions 17 and 19 comprises at least one respective pocket of fabric.
Each pocket of fabric forming the two side portions 17, 19 comprises partial rows of stitches having gradually decreasing and gradually increasing lengths produced with reciprocating motion of the needle cylinder. Vice versa, the central portion 15 of the body 7 can be advantageously knitted with continuous motion of the needle cylinder, similarly to the leg pieces.
In all the knitting steps, the needles of the cylinder are fed with at least two feeds, i.e. with at least two yarns. In preferred embodiments, four feeds are provided to feed four yarns to the circular bed of needle A of the cylinder 101. If the diameter dimension of the needle cylinder allows it, the number of feeds can be also greater than four, for instance six or more feeds. In this way the time necessary to produce the article or garment is reduced and the finished product has a greater quality. In fact, at every rotation of the needle cylinder 101 a number of (complete or partial) rows is formed equal to the number of fed yarns.
Thanks to the pockets 17, 19 of fabric the snug-fit of the garment is improved, the elasticity of the body central portion is not limited and the article or garment can be therefore used also by people wearing relatively large sizes.
In some embodiments the article or garment 1 is produced with a single knitting operation on a circular machine, for instance a single-cylinder circular machine with dial, as the case may be.
The knitting process is substantially comprised of a sequence of steps, at the end whereof a complete article with body and tubular leg pieces is produced. More in particular, the knitting process may be for instance subdivided into seven consecutive steps, as it will be explained below.
The knitting process can indifferently start from the tubular leg piece 3 or from the tubular leg piece 5. For the sake of practicality of the description, reference will be made below to a process starting with the knitting of the tubular leg piece 3 and ending with the knitting of the tubular leg piece 5, being however understood that the process can be reversed, starting with the knitting of the tubular leg piece 5 and ending with the knitting of the tubular leg piece 3.
In a first knitting step on the circular knitting machine 101 (
For knitting the tubular leg piece 3 it is possible to feed the circular bed of needles A with one or more feeds, i.e. with one or more yarns. At least four feeds are preferably used and more in general an even number of feeds, for instance six feeds. In this way, every time the needle cylinder rotates, a number of rows is formed equal to the number of feeds.
With at least two feeds, coated yarns of the Z-type or S-type can be used, i.e. for instance yarns with an elastomer core coated by filaments twisted clockwise (Z-yarn) and counterclockwise (S-yarns). As it is well known to those skilled in the art, the use of Z-yarns and S-yarns at the same time allows a better consistency of the article, which does not tend to twist.
Instead of using S-yarns and Z-yarns in combination, it is possible to use so called doubled yarns, i.e. wherein coating yarns are twisted around an elastomer core according to opposite helices, so that the yarn does not tend to twist. The doubled yarns are however more expensive than S-twist and Z-twist yarns; therefore the opportunity of using Z-yarns and S-yarns instead of doubled yarns is a significant economic advantage.
The knitting of the tubular leg piece 3 ends with the formation of a last circular row of stitches, indicated with 23. The complete row 23 is preferably comprised of a number of stitches equal to the number of needles with which the circular knitting machine is provided, even if this is not compulsory. It is only important that this row is complete, i.e. it extends around the whole leg piece.
Rows of stitches extending substantially horizontally, indicated with RG3 in
A second step of the process is then performed on the circular knitting machine; this step consists of knitting a first series of partial rows of gradually decreasing length with reciprocating motion to form a first portion 17D of the pocket 17 of fabric. How this portion of pocket and the remaining portions of the pockets 17, 19 are formed will be described in greater detail here below, with reference to
Similarly to the leg pieces, also the portion 17D of the pocket 17 is knitted with a plurality of feeds. Preferably, a number of feeds is used equal to the number of feeds used for knitting the first tubular leg piece 3, i.e. at least two and preferably at least four or more feeds.
The portion 17D of the pocket 17 can be formed with the same yarns used for knitting the tubular leg piece 3. In other embodiments some or all yarns may be replaced, so that the portion 17D of the pocket 17 is formed with a number of yarns equal to the number of yarns used for the leg piece 3, but these yarns are of different type; for instance, these yarns may have different denier, or different composition or structure. In some embodiments the type of yarn may be changed once or more times while knitting the portion 17D of the pocket 17.
While the portion 17D of the pocket 17 is being formed, partial rows of stitches, indicated with R17, are sequentially knitted, whose length gradually decreases starting from the last complete row 23, formed while knitting the leg piece 3, up to a row RM17 of minimal length, ending this second step of the knitting process. More precisely, as also the pocket 17 of fabric is knitted with a plurality of feeds and therefore forming a plurality of rows at every revolution of the needle cylinder 101 in one direction or in the opposite direction, the knitting of the portion 17D of the pocket 17 ends with the formation of a number of rows RM17 of minimal length equal to the number of feeds used in this step, for instance four feeds.
The row or group of rows RM17 of minimal length extends from one end point to the other, both indicated with C1, of two opposite lines L17.
As it will be greater detailed below, the single rows formed with the yarns from the various feeds at every reciprocating stroke, i.e. at every rotation of the needle cylinder 101 in one direction or in the opposite direction in the reciprocating motion, are shifted with respect to one another by one or more stitches, preferably by two or more stitches, more preferably by three or more stitches, for instance by from 3 to 10 stitches, for the purposes that will be clearly apparent to those skilled in the art from the detailed description below.
The first group of partial rows knitted while knitting the portion 17D of the pocket 17 of fabric, indicated as a whole with Rx17 in
Essentially, the partial rows of the portion 17D knitted in succession by cyclically reversing the direction of rotation of the needle cylinder 101 have therefore gradually decreasing length, i.e. a gradually reduced number of stitches, as they are knitted by excluding from work a gradually increasing number of needles up to the formation of the plurality of partial rows RM17 of minimal length.
Moreover, all the rows formed during a single reciprocating stroke in one direction (clockwise or counterclockwise) with the yarns from the various feeds have preferably the same number of stitches, i.e. the same length. However, the rows formed during each reciprocating stroke or oscillation of the needle cylinder 101 are shifted with respect to one another, i.e. the end stitches of the single rows of equal length are not aligned with one another on a single column but they are shifted by a given number of stitches.
The ends of the partial rows following one another along the portion 17D of the pocket 17 are arranged according to the two opposite delimiting lines L17 extending in an inclined fashion (one on the front and the other on the back of the garment) from the row 23 up to the rows RM17 of minimal length. It must be understood that, even if not shown in the drawing, in the area of the pocket 17 there are actually two substantially mirror-like lines L17, one on the front and the other on the back. These opposite lines L17 are constituted by the alignment of the ends of the partial rows formed in this step of the knitting process.
Once this portion 17D of the pocket 17 has been completely formed, the subsequent step of knitting a second portion labeled 17C of pocket 17 starts. Also the portion 17C of pocket 17 is knitted with a reciprocating motion of the needle cylinder and with gradual increase, i.e. with a gradual increase in the length of the rows following one another while knitting this portion 17C of the pocket 17. Also the portion 17C of the pocket 17 is formed by feeding the needle cylinder 101, which rotates with reciprocating motion, with yarns from a plurality of feeds, preferably the same number of feeds as those used for knitting the leg piece 3 and the portion 17D of the pocket 17.
Therefore, as already described with reference to the rows of decreasing length forming the portion 17D of the pocket 17, while forming the portion 17C of the pocket 17, at every rotation of the needle cylinder 101 in one direction or in the opposite direction, groups of rows are actually formed, each group comprising a number of rows equal to the number of feeds. In the illustrated embodiment, the rows of each group have the same length, i.e. they are comprised of the same number of stitches. This is preferred, but not strictly necessary. In other embodiments the rows of each group may have different length from one another.
Moreover, even if the rows of each group have the same length, they are shifted with respect to one another, similarly to the rows of the groups formed while knitting the portion 17D. The number of stitches, and thus the length of the partial rows, gradually increases from a group of rows to the following one, starting from the minimal length of the rows RM17.
The various partial rows formed during the third step of the knitting process for forming the portion 17C of the pocket 17 join at their ends the partial rows of decreasing length forming the portion 17D. The decreasing partial rows and the increasing partial rows join together along the line L17 as it will be better described below with reference to
The knitting of the portion 17C of the pocket 17 continues with gradual increase in the length of the single partial rows R17 up to the formation of the last partial row, or more exactly of the last group of partial rows, of the portion 17C, that is indicated with Ry17.
Now the fourth step of the knitting process begins, made with continuous motion of the needle cylinder 101 and starting again from the first complete row 25. The row 25 has an annular extension and is preferably formed by a number of stitches equal to the overall number of needles of the machine. In this fourth step the central portion 15 of the body 7 is knitted with continuous motion of the needle cylinder 101, the needles forming a sequence of complete rows 25X that have annular extension and are substantially parallel to the row 25. The formation of a last complete row 27 concludes the knitting of the central portion 15 of the body 7.
As shown in particular in
In the subsequent fifth knitting step two portions 19D and 19C of the pocket 19 of fabric are formed, using a process essentially symmetrical to that used for forming the pocket 17. While knitting the pocket 19 of fabric a plurality of feeds is used, preferably equal to the number of feeds used in the previous four steps of the knitting process. Every time the needle cylinder 101 rotates in one direction or in the opposite direction, rows are formed in a number equal to the number of feeds and having the same length. The rows, formed at every rotation or reciprocating stroke in one direction or in the opposite direction and preferably having the same length, are shifted with respect to one another. Every time the motion is reversed, the length of the rows decreases, preferably by two stitches.
More in particular, the fifth step of the knitting process comprises the formation of a series of partial rows of gradually decreasing length with reciprocating motion of the needle cylinder 101, starting from the row 27 completing the central portion 15 of the body 7. Rx19 indicates the first group of partial rows. Similarly to the rows Ry17, the partial rows Rx19 can have a number of stitches equal to nearly the half of the number of needles of the cylinder 101. The rows following the partial rows Ry19 are indicated with R19 and have gradually decreasing length.
The partial rows forming the portion 19D of the pocket 19 have ends arranged along two lines L19, only one of which is shown in the drawing and the other one is the mirror of this. The lines L19 are essentially symmetrical to the lines L17.
The formation of a group of partial rows of minimal length indicated with RM19 concludes the fifth step of the knitting process; these partial rows extend from one end point C2 to the other of the two opposite lines L19.
After this fifth knitting step, the sixth knitting step begins, consisting in the formation of the second portion 19C of the pocket 19. In this sixth step partial rows of stitches of gradually increasing length are formed, indicated again with R19, starting from the rows RM19 of minimal length up to a last group of partial rows Ry19 of maximum length. The number of rows formed at every rotation in one direction or in the other direction is equal to the number of feeds and these rows have preferably the same length but they are shifted with respect to one another, as already described with reference to the knitting of the portion 17C.
The subsequent seventh step is the last step of the knitting process; it begins with the formation of a complete row 29 with annular extension preferably formed by a number of stitches equal to the number of needles available on the machine. The knitting continues, forming continuous rows RG5 from the start row 29, constituting the beginning of the tubular leg piece 5, up to the last row of the end thereof (not shown). Starting from the row 29, the knitting is made with continuous motion of the needles and with a number of feeds preferably equal to the number of feeds used for forming the previous portions of the article or garment, for instance four feeds.
Symmetrically to what described with reference to the pocket 17 and the tubular leg piece 3, along the portion 19D of the pocket 19 the columns CC of stitches are arranged substantially parallel to the edge 11, while along the portion 19C and along the leg piece 5 the columns are arranged according to the longitudinal extension of the tubular leg piece 5 as schematically shown by lines CGS.
The process for forming the pockets 17, 19 of fabric with reciprocating motion will be described below in greater detail with reference to
Reference will be made below to the step of knitting the pocket 17 that (as briefly described above) begins with the formation of a portion 17D of gradually decreasing rows, i.e. with an area where the row length decreases, followed by the knitting of the area 17C with gradual increase in the length of the partial rows. From the description of these two steps of the knitting process it is easy to understand how the pocket 19 is knitted in a corresponding way.
Below a process will be described, wherein the length of the partial rows decreases in a uniform and linear manner, i.e. at every rotation or pendulum motion of the needle cylinder 101 there is an equal reduction in the length of the rows, said length being understood as the number of stitches forming the single row. Those skilled in the art will understand that this is the preferred operating process, but that the method described herein can be also implemented in a different way, for instance reducing the length of the partial rows by a different number of stitches in subsequent cycles, i.e. reciprocating strokes, while knitting the pocket of fabric.
The pattern of decreases and increases, i.e. of the rows of increasing and decreasing length, in the two pockets 17 and 19 will be preferably mirror-like, but the sequence does not necessarily need to be equal for the front and the rear part of the garment. This means that subsequent rows of different lengths may be increased or decreased in length in a different manner on the two parts (front and rear) of the fabric. In the description below it has been assumed that, every time the motion is reversed, the length of the rows of stitches is reduced by one stitch at each end.
In
With initial reference to
All the needles A1-A400 of the machine are active and form, with the yarns F1-F4, the last four complete rows, indicated with RG3 in
With reference to
With reference to
With reference to
When the continuous motion of the needle cylinder 101 in counterclockwise direction is finished, four partial rows have been therefore formed, ending with respective last stitches formed by means of the needles A200 (for the yarn F1 of the first feed), A197 (for the yarn F2 of the second feed), A194 (for the yarn F3 of the third feed), and A191 (for the yarn F4 of the fourth feed). These shifted ends of the four rows RxF1-RxF4 are arranged along the line L17 (
With reference to
With reference to
With reference to
With reference to
The needle cylinder 101 continues to rotate clockwise, as shown in
The needle cylinder 101 continues to rotate clockwise until the partial row RF1 has been completely formed, as shown in
The needle cylinder 101 continues to rotate clockwise up to the position shown in
The result of this process is shown clearly in
the row RF4 is formed by the stitches formed by the needles A190 up to A2;
the row RF3 is formed by the stitches formed by the needles A193 up to A5;
the row RF2 is formed by the stitches formed by the needles A196 up to A8;
the row RF1 is formed by the stitches formed by the needles A199 up to A11.
However, the end stitches of the various partial rows formed with the different feeds during an angular stroke, i.e. during an oscillation or reciprocating stroke of the rotary motion of the needle cylinder 101, are not aligned on the same column of stitches, but they are shifted.
In other embodiments each row formed by a yarn can be reduced, at both ends thereof, by more than one stitch with respect to the previous row.
Still referring to
When the knitting motion starts again in counterclockwise direction, starting from the position shown in
Similarly, the yarn F2 of the second feed begins to form stitches starting from the needle A9, adjacent to the needle A8 that has formed the last stitch in the previous clockwise movement, and ends the formation of the partial row RF2′ with the stitch formed by means of the needle ago A195, being thus shorter by two stitches with respect to the row RF2 previously formed with the same feed. The two rows RF1′, RF2′ are shifted with respect to each other by three stitches (the row RF1′ starts from the needle A12 and ends at the needle A198, while the row RF2′ starts from the needle A9 and ends at the needle A195).
As it is shown in
In the described embodiment, the needles are selected so that the rows formed with the four feeds are shifted by three stitches with respect to one another in an ordered manner, i.e. for instance the start ends of the rows RF1-RF4 are shifted three by three, starting from the row formed with the first feed (yarn F1) up to the row formed with the fourth feed (yarn F4). At the opposite end, the start points of the rows RF1′-RF4′ are shifted reversely, starting from the first stitch formed with the yarn F4 up to the first stitch formed with the yarn F1. However, this is not strictly necessary; in some cases the sequences can be modified, as it will be clearly apparent below.
As a result of the described knitting process, along the lines L17 of the pocket 17 of fabric the ends of the partial rows R17 (that in the detail of
Once the decreasing partial rows forming the portion 17D of the pocket 17 have been knitted, the process continues forming partial rows of gradually increasing length, as shown in
For the sake of clarity, the sequences of
More in particular,
It should be understood that in the schematic example of
Once the last partial rows have been completed along the line 25, the needle cylinder 101 starts to rotate counterclockwise again for forming the central portion 15 of the body 7 with continuous motion.
The pocket 19 of fabric is made according to the same procedure described with reference to
Similarly to the portion 17C, the formation of the portion 19C of fabric starts with a gradual increase in the length of the rows, from the minimal length of the rows RM19 up to the maximum length of 190 stitches of the last four partial rows formed with the yarns from the four feeds during the last partial rotation of the reciprocating motion. Then, the knitting continues with continuous motion in counterclockwise direction to form the tubular fabric of the second leg piece 5.
With reference to
However, this particular reversed sequence is not strictly necessary, even if it is preferred, as it results in an easier movement of the yarns.
However, the partial rows of decreasing and increasing length are always shifted with respect to one another, as in the example of embodiment of
Analogously to
C1 and C2 indicate respectively the cams for lifting and lowering the needles. A pair of cams C1, C2 is associated with each feed G1-G4. C3 indicates auxiliary cams for lowering the needles, which operate only while knitting with reciprocating motion, as it will be better explained below. The auxiliary cams C3 are retracted inside the support during continuous-motion knitting, so that they do not act on the heels of the needles A. In
As it is clear from the description of the cam support and from the process of knitting the pockets of fabric, with specific reference to
Even if in the illustrated embodiment the body is formed with only two side pockets of fabric knitted with reciprocating motion, in other embodiments a greater number of pockets may be formed, for instance two pockets of fabric on each side of the body.
In the process described above it is assumed that an article or garment is produced with a body and two leg pieces, which is completely closed when it is removed from the circular knitting machine, i.e. without openings for wearing the garment, and only provided, as the case may be, with openings in correspondence of the ends of the leg pieces. The opening in correspondence of the waist for wearing the garment is produced once the garment has been removed from the machine, by cutting along the line 13 and applying an elastic edge 11 according to known methods.
In some embodiments, the cutting device 201 comprises an electrical resistor 203, i.e. an element that is heated by Joule effect by means of a current flowing through it.
The electrical resistor 203 can be electrically connected to two electric wires by means of a connector 205. Each electric wire 207 is into electric contact with a contact brush 208. These contact brushes power the electric resistor 203 while it rotates together with the cylinder 101 of the needles A.
The electric resistor 203 and the connectors 205 can be supported by an annular support element 209 surrounding the axis A-A of the needle cylinder and rotating with the needle cylinder 101. The support element 209 is provided with a vertical movement, i.e. a movement parallel to the axis A-A of the needle cylinder, according to the arrow f209, so as to take alternatively two positions shown respectively in
In
The lifting and lowering movement of the electric resistor 203 is synchronized with the knitting process, so that the opening is made in the required position.
According to some embodiments, the operation of the cutting device 201 can be such as to act on the knitted article once the knitting has been stopped. For instance, it is possible firstly to knit a first portion of the body as described above and then activate the cutting device 201. The knitting machine is stopped and the device 201 is lifted to cut an opening portion in the garment held on the needle cylinder. Then, the cutting device 201 is lowered, i.e. it is made inactive and knitting starts again to form a subsequent portion of the article or garment 1. Then the knitting machine is stopped again and the cutting process is repeated by lifting the cutting device again. The process is repeated until an opening of sufficient length is made. This process requires time but the cutting device 201 does not necessarily need to rotate in synchronous way with the needle cylinder 101.
According to preferred embodiments, to accelerate the knitting process, the cutting device 201 rotates together with the needle cylinder 101. In this way the cutting device 201 can be lifted and held in lifted active position for the time necessary to knit the portion of body that shall be cut (yarn melting). Once a sufficiently long opening has been made, the knitting continues while the cutting device 201 is made inactive and brought into the lowered inactive position.
The ring 213 can be provided with an annular channel 215 engaging rollers or wheels 217 that can be supported by a movable arm 219 ending with a distal portion 219A in the shape of a fork, carrying the wheels 217. In some embodiments, the arm 219 may be articulated to a stationary structure of the knitting machine around a horizontal axis. An actuator 221 can be provided to oscillate the arm 219 according to the double arrow f219. The oscillation of the arm 2189 controls the lifting and lowering movement of the ring 213 and of the support element 209 by means of the upright 211. The wheels 217 engage in the annular channel 215 and allow the upright 211, the ring 213 and the support element 209 to rotate together with the needle cylinder 101 around the axis A-A of the same cylinder. In this way, the electric resistor 203 can rotate together with the needle cylinder 101 and can move vertically according to the arrow f209 from the position of
In other embodiments a different cutting device may be used, for instance comprising a laser source, or a mechanical cutting device instead of the electric resistor 203. In some embodiments, for instance, when a laser beam is used, the vertical movement for actuating and deactuating the cutting device may be omitted.
As can be seen in particular in the enlargements of
Similarly to the previously described embodiment shown e.g. in
Moreover, in the embodiment of
Let's consider by way of example yarn F3, but the same holds true for the remaining yarns F1, F2, F4. In
Upon reversal of the needle cylinder rotation, the same yarn F3 starts with the formation of a next row or course of stitches Ry. The first stitch (
The embodiments described above and illustrated in the drawings have been explained in detail as examples of embodiment of the invention. It will be clearly apparent to those skilled in the art that modifications, variants, additions and omissions are possible, without however departing from the principles, the scope of the concept and the teachings of the present invention as defined in the attached claims. The scope of the invention shall be therefore determined exclusively based upon the widest interpretation of the attached claims, wherein these modifications, variants, additions and omissions are included within this scope. The terms “comprising” “to comprise” and the like do not exclude the presence of further elements or steps in addition to those specifically listed in a claim. The term “a” or “an” before an element, means or feature of a claim does not exclude the presence of a plurality of these elements, means or features. If a claim of a device claims a plurality of “means”, some or all these “means” can be actuated by a single component, member or structure. The enunciation of given elements, features or means in distinct depending claims does not exclude the possibility of combining said elements, features or means together. When a method claim lists a sequence of steps, the sequence with which these steps are listed is not binding and can be changed, if the particular sequence is not indicated as binding. Any reference numerals in the appended claims are provided to facilitate reading of the claims with reference to the description and to the drawing, and do not limit the scope of protection represented by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| FI2013A0247 | Oct 2013 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2014/072295 | 10/17/2014 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2015/055803 | 4/23/2015 | WO | A |
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| Number | Date | Country | |
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| 20160251783 A1 | Sep 2016 | US |
